Failed closure of the neural tube, the embryonic structure from which the brain and spinal cord are formed, leads to neural tube defects (NTDs). The NTD complex includes the two most common forms of NTDs, spina bifida and anencephaly, as well as other less frequent manifestations such as encephalocele, craniorachischisis, and iniencephaly. The frequency of NTD births in the United States is approximately 1/1000, making it the second most common birth defect in humans. Numerous studies have implicated both environmental and genetic factors. A plethora of mouse and other experimental models exist and are invaluable for understanding the developmental biology of NTDs, developing potential model systems for interventions and/or preventions, and for testing the effects of various environmental risk factors. The identification of a substantial risk for NTD birth following periconceptional supplementation with folic acid has represented a substantial breakthrough for prevention, but the mechanisms for its action are unclear. Despite decades of study, very little progress in understanding the genetic basis of NTDs and the relationship between genes and the environment has been made. Given the complexity of this condition, developing relationships and collaborations across a variety of disciplines is key to ensuring rapid development in this area. The goal of this proposal is to bring together researchers from a variety of fields including human genetics, embryology, dysmorphology, epidemiology, animal modeling, developmental biology, toxicology, nutrition, and molecular biology to share research findings, ideas, and goals and to establish new collaborations and new avenues of research. This conference will provide ample forum for formal and informal interactions between investigators and further the collaborative relationships across the world in this discipline. This conference has been on-going since 1999, and the conference developers and attendees are grateful for NIH support (primarily NINDS) since the second iteration of this conference. The 2007 conference will be held September 24-27, 2007 at the Asilomar Conference Center in Monterey, California. Statement The relevance of this project relates to its ability to convene an educational meeting of interested individuals who will form collaborations that will lead to advances in the study of Neural Tube Defects. These meetings will expand the field of NTD research and connect those involved to improve coordination of projects and ensure the most efficient use of funds. [unreadable] [unreadable] [unreadable]